Process for producing silicon and oxide films from organoaminosilane precursors

ABSTRACT

A method for depositing a silicon containing film on a substrate using an organoaminosilane is described herein. The organoaminosilanes are represented by the formulas: 
                         
wherein R is selected from a C 1 -C 10  linear, branched, or cyclic, saturated or unsaturated alkyl group with or without substituents; a C 5 -C 10  aromatic group with or without substituents, a C 3 -C 10  heterocyclic group with or without substituents, or a silyl group in formula C with or without substituents, R 1  is selected from a C 3 -C 10  linear, branched, cyclic, saturated or unsaturated alkyl group with or without substituents; a C 6 -C 10  aromatic group with or without substituents, a C 3 -C 10  heterocyclic group with or without substituents, a hydrogen atom, a silyl group with substituents and wherein R and R 1  in formula A can be combined into a cyclic group and R 2  representing a single bond, (CH 2 ), chain, a ring, C 3 -C 10  branched alkyl, SiR 2 , or SiH 2 .

CROSS REFERENCE TO RELATED APPLICATION

The present patent application is a continuation-in-part of U.S. patentapplication Ser. No. 11/439,554 filed May 23, 2006 now issued U.S. Pat.No. 7,875,312 and is a continuation of U.S. patent application Ser. No.12/976,041 filed Dec. 22, 2010.

BACKGROUND OF THE INVENTION

In the fabrication of semiconductor devices, a thin passive layer of achemically inert dielectric material such as a silicon-containing filmis essential. Thin layers of silicon-containing films such as siliconoxide function as insulators between polysilicon and metal layers,diffusion masks, oxidation barriers, trench isolation, intermetallicdielectric material with high dielectric breakdown voltages andpassivation layers.

The following articles and patents are cited as representative of theart with respect to the synthesis of deposition processes employed inthe electronics industry for producing silicon oxide films.

U.S. Pat. No. 5,250,473 discloses a method of providing a silicondioxide layer having a substantially uniform thickness at an improveddeposition rate on a substrate by means of low pressure chemical vapordeposition (LPCVD). The reactants generally comprise mixture of anoxidizing agent and a chlorosilane, wherein the chlorosilane is amonochlorosilane of the formula R₁R₂SiHCl and where R₁ and R₂ representan alkyl group. The silicon dioxide layer may be deposited on varioussubstrates such as aluminum.

U.S. Pat. No. 5,382,550 discloses a CVD process for depositing SiO₂ filmon a semiconductor substrate. An organosilicon compound, e.g.,tetraethylorthosilicate (TEOS) or ditertiarybutylsilane is used asprecursor.

U.S. Pat. No. 6,391,803 discloses a process for producing siliconnitride and silicon oxide films using ALD and employing compounds of theformula: Si[N(CH₃)₂]₄, SiH[N(CH₃)₂]₃, SiH₂[N(CH₃)₂]₂ or SiH₃[N(CH₃)₂].Trisdimethylaminosilane (TDMAS) is preferred as a precursor.

U.S. Pat. No. 6,153,261 discloses a method for increasing the depositionrate in the formation of silicon oxide, silicon nitride and siliconoxynitride films which comprises using bistertiarybutylaminosilane(BTBAS) as a precursor reactant.

U.S. Pat. No. 6,974,780 discloses a process for depositing SiO₂ films ona substrate using a CVD reactor. Silicon precursors, such as TEOS,diethylsilane, tetramethylcyclo-tetraoxysilioxane, fluorotriethoxysilaneand fluorotrialkoxysilane, in combination with water and hydrogenperoxide are used as reactants.

BRIEF SUMMARY OF THE INVENTION

Described herein is a method for depositing a stoichiometric ornon-stoichiometric silicon and oxide containing film such as, but notlimited to, a silicon oxide film, a silicon oxynitride film, a siliconoxycarbide film, or a silicon oxycarbonitride film onto at least aportion of a substrate. In one embodiment of the method describedherein, a layer comprising silicon and oxide is deposited onto asubstrate using a silane precursor and an oxidizing agent in adeposition chamber under conditions for generating a silicon oxide layeron the substrate. In the process described herein, an organoaminosilanehaving Formula A through Formula C described herein is employed as thesilane precursor.

The classes of compounds employed as the precursor are generallyrepresented by the formulas:

and mixtures thereof, wherein R is selected from a C₁-C₁₀ linear,branched, or cyclic, saturated or unsaturated alkyl group with orwithout substituents; a C₅-C₁₀ aromatic group with or withoutsubstituents, a C₃-C₁₀ heterocyclic group with or without substituents,or a silyl group in formula C with or without substituents, R¹ isselected from a C₃-C₁₀ linear, branched, cyclic, saturated orunsaturated alkyl group with or without substituents; a C₅-C₁₀ aromaticgroup with or without substituents, a C₃-C₁₀ heterocyclic group with orwithout substituents, a hydrogen atom, a silyl group with substituentsand wherein R and R¹ in formula A also being combinable into a cyclicgroup and R² representing a single bond, (CH₂), chain, a C₃-C₁₀ branchedalkyl, a ring, SiR₂, or SiH₂. Preferred compounds are such that both Rand R¹ have at least 2 carbon atoms. In one particular embodiment, thesilane precursor has the formula A wherein both R and R¹ are isopropyl.In another particular embodiment, the organoaminosilane precursor hasthe formula A wherein R is n-propyl and R¹ is isopropyl. In yet anotherembodiment, the organoaminosilane precursor has the formula A wherein Ris isopropyl, R¹ is sec-butyl and R and R¹ are also combined to form aheterocyclic group.

In one particular embodiment, there is provided a method for forming asilicon oxide film on a substrate comprising: reacting an oxidizingagent with a precursor comprising at least one organoaminosilaneprecursor selected from the group consisting of an organoaminosilanerepresented by the formulas:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic,saturated or unsaturated alkyl group with or without substituents; aC₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀heterocyclic group with or without substituents, or a silyl group informula C with or without substituents, R¹ is selected from a C₃-C₁₀linear, branched, cyclic, saturated or unsaturated alkyl group with orwithout substituents; a C₅-C₁₀ aromatic group with or withoutsubstituents, a C₃-C₁₀ heterocyclic group with or without substituents,a hydrogen atom, a silyl group with substituents and wherein R and R¹ informula A also being combinable into a heterocyclic group and R²representing a single bond, (CH₂), chain, a C₃-C₁₀ linear, branched, aring, SiR₂, or SiH₂ in a vapor deposition to form the silicon oxide filmon the substrate.

In another embodiment, there is provided a method for forming a siliconoxide film on a substrate comprising: forming via vapor deposition ofthe silicon oxide film on the substrate from a composition comprising atleast one organoaminosilane precursor selected from the group consistingof an organoaminosilane represented by the formulas:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic,saturated or unsaturated alkyl group with or without substituents; aC₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀heterocyclic group with or without substituents, or a silyl group informula C with or without substituents, R¹ is selected from a C₃-C₁₀linear, branched, cyclic, saturated or unsaturated alkyl group with orwithout substituents; a C₅-C₁₀ aromatic group with or withoutsubstituents, a C₃-C₁₀ heterocyclic group with or without substituents,a hydrogen atom, a silyl group with substituents and wherein R and R¹ informula A also being combinable into a heterocyclic group comprisingfrom 2 to 6 carbon atoms and R² representing a single bond, (CH₂),chain, a C₃-C₁₀ linear, branched, a ring, SiR₂, or SiH₂ at least oneoxidizing agent, wherein the vapor deposition is at least one selectedfrom chemical vapor deposition, low pressure vapor deposition, plasmaenhanced chemical vapor deposition, cyclic chemical vapor deposition,plasma enhanced cyclic chemical vapor deposition, atomic layerdeposition or plasma enhanced atomic layer deposition.

In yet another embodiment, there is provided a method for forming asilicon oxide film on a substrate comprising: introducing anorganoaminosilane represented by one of the following formulas:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic,saturated or unsaturated alkyl group with or without substituents; aC₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀heterocyclic group with or without substituents, or a silyl group informula C with or without substituents, R¹ is selected from a C₃-C₁₀linear, branched, cyclic, saturated or unsaturated alkyl group with orwithout substituents; a C₅-C₁₀ aromatic group with or withoutsubstituents, a C₃-C₁₀ heterocyclic group with or without substituents,a hydrogen atom, a silyl group with substituents and wherein R and R¹ informula A also being combinable into a heterocyclic group comprisingfrom 2 to 6 carbon atoms and R² representing a single bond, (CH₂),chain, a C₃-C₁₀ linear, branched, a ring, SiR₂, or SiH₂ into adeposition chamber; introducing at least one oxidizing agent into thedeposition chamber wherein the at least one oxidizing agent reacts withthe organoaminosilane to provide the silicon oxide film on thesubstrate.

The precursors described herein when employed in CVD or ALD processescan at least one or more of the following advantages, such as, but notlimited to:

an ability to facilitate formation of dielectric films at low thermalconditions such as but not limited to room temperature (e.g., 25° C.),100° C. or less, 250° C. or less, without incurring the problems ofplasma deposition;

an ability to mix the organoaminosilane having the Formula A through Cdescribed herein with other precursors, e.g., ammonia at variousstoichiometries, other silicon precursors, etc., for permitting controlof the ratio of Si—C, Si—N, or Si—O and thereby control thecharacteristics of the resulting films;

an ability to produce films having relatively high refractive indicesand film stresses compared to comparative films prepared by otheraminosilane precursors;

an ability to produce films having low acid etch rates compared tocomparative films prepared by other aminosilane precursors;

an ability to produce films of high densities compared to comparativefilms prepared by other aminosilane precursors;

an ability to generate films while avoiding chlorine contamination;

an ability to operate at low pressures (20 mTorr to 2 Torr) in amanufacturable batch furnace (100 wafers or more); and,

an ability to generate silicon-containing films at low temperatures,e.g., as low as 550° C. and below, or 300° C. and below, or 100° C. andbelow.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 a and FIG. 1 b provides the Fourier Transform spectroscopyspectra for silicon oxide films deposited at 150° C. and 300° C.,respectively, from the organoaminosilane precursorsdiisopropylaminosilane, bis(di-isopropylamino)silane anddi-n-butylaminosilane.

DETAILED DESCRIPTION OF THE INVENTION

The formation of silicon oxide films on semiconductor substrates viachemical vapor deposition (CVD) and atomic layer deposition (ALD) arewell established and the deposition processes employed can be usedherein to form the silicon and oxide containing films described hereinusing at least one organoaminosilane precursor having Formula A throughC described herein.

The method used to form the dielectric films or coatings are depositionprocesses. Examples of suitable deposition processes for the methoddisclosed herein include, but are not limited to, cyclic CVD (CCVD),MOCVD (Metal Organic CVD), thermal chemical vapor deposition, plasmaenhanced chemical vapor deposition (“PECVD”), high density PECVD, photonassisted CVD, plasma-photon assisted (“PPECVD”), cryogenic chemicalvapor deposition, chemical assisted vapor deposition, hot-filamentchemical vapor deposition, CVD of a liquid polymer precursor, depositionfrom supercritical fluids, and low energy CVD (LECVD). The silicon andoxide containing films may be formed in deposition chambers designed forchemical vapor deposition (CVD), low pressure chemical vapor deposition(LPCVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD), andso forth. The term CVD as used herein is intended to include each ofthese processes which are employed in the semiconductor industry. Incertain embodiments, the silicon and oxide containing films aredeposited via plasma enhanced ALD (PEALD) or plasma enhanced cyclic CVD(PECCVD) process. As used herein, the term “chemical vapor depositionprocesses” refers to any process wherein a substrate is exposed to oneor more volatile precursors, which react and/or decompose on thesubstrate surface to produce the desired deposition. As used herein, theterm “atomic layer deposition process” refers to a self-limiting (e.g.,the amount of film material deposited in each reaction cycle isconstant), sequential surface chemistry that deposits conformal films ofmaterials onto substrates of varying compositions. Although theprecursors, reagents and sources used herein may be sometimes describedas “gaseous”, it is understood that the precursors can be either liquidor solid which are transported with or without an inert gas into thereactor via direct vaporization, bubbling or sublimation. In some case,the vaporized precursors can pass through a plasma generator. In oneembodiment, the film is deposited using an ALD process. In anotherembodiment, the film is deposited using a CCVD process. In a furtherembodiment, the film is deposited using a thermal CVD process.

In certain embodiments, the method disclosed herein avoids pre-reactionof the precursors by using ALD or CVD methods that separate theprecursors prior to and/or during the introduction to the reactor. Inthis connection, deposition techniques such as an ALD or CVD processesare used to deposit the dielectric film. In one embodiment, the film isdeposited via an ALD process by exposing the substrate surfacealternatively to the one or more the silicon-containing precursor,oxygen source, or other precursor or reagent. Film growth proceeds byself-limiting control of surface reaction, the pulse length of eachprecursor or reagent, and the deposition temperature. However, once thesurface of the substrate is saturated, the film growth ceases.

In certain embodiments of the above processes, a reactor chamber isevacuated and a semiconductor substrate placed therein. Then, one ormore silane precursors and an oxidizing source are provided to thereactor chamber under conditions wherein a silicon oxide layer is formedon the semiconductor wafer. These films also may be adjusted for carbon,nitrogen and hydrogen content (sometimes referred to as doping) duringthe process by the addition of carbon, hydrogen and nitrogen sources.The resulting films produced by the use of the organoaminosilaneprecursors are often referred to as silicon oxide, silicon oxycarbide,silicon oxynitride and silicon carbooxynitride films.

One class of silicon compound suited for the practice of this inventionis an organoaminosilane precursor and it is represented by formula A asfollows:

In Formula A, R is selected from a C₁-C₁₀ linear, branched, cyclic,saturated, or unsaturated alkyl group with or without substituents; aC₆-C₁₀ aromatic group with or without substituents; or a C₃-C₁₀heterocyclic group with or without substituents; R¹ is selected from aC₃-C₁₀ linear, branched, cyclic, saturated, or unsaturated alkyl groupwith or without substituents; a C₆-C₁₀ aromatic group with or withoutsubstituents; a C₃₋₁₀ heterocyclic aromatic group with or withoutsubstituents; a C₃-C₁₀ heterocyclic group with or without substituents;a hydrogen atom; or a silyl group with substituents; or wherein R andWare combined into a heterocyclic group via formation of single ordouble carbon-carbon bond or linkage through oxygen or nitrogen atom.Representative groups for R and R¹ are alkyl groups and particularly theC₂₋₄ alkyl groups, such as ethyl, n-propyl, isopropyl, n-butyl,iso-butyl, sec-butyl, tert-butyl, and cyclic groups such as cyclopropyl,cyclobutyl, cyclopentyl, and cyclohexyl. Illustrative of some of thepreferred compounds within this class are represented by the formulas:

wherein n ranges from 2 to 6 or from 4 to 5. In certain embodiments, Rand R¹ are the same. In other embodiments, R and R¹ are different. Inone particular embodiment of the organoaminosilane precursors havingFormula A, R is n-propyl and R¹ is isopropyl. In another embodiment ofthe organoaminosilane precursors having Formula A, R is an aromaticgroup with or without substituents and R¹ is a linear or branched alkylgroup. In a further embodiment of Formula A, R is a methyl group and R¹is a phenyl group. In yet a further embodiment of Formula A, R is anisopropyl group, R¹ is a sec-butyl group and R and R¹ are combined toform a 5 or 6 member cyclic group. In yet a further embodiment ofFormula A, R and R¹ are combined to form a 5 or 6 member heterocyclicaromatic group including, but no limited to, pyrrole, alkyl substitutedpyrrole, imidozale, alkyl substituted imidozale, pyrozale, or analkyl-substituted pyrozale. In a still further embodiment of Formula A,both R and R¹ are not isobutyl or n-butyl groups.

The second class of organoaminosilane precursor suited for use inproducing silicon oxide layers is an organoaminosilane which has twosilyl groups pendant from a single nitrogen atom as represented byformula B.

As with the R groups of the Class A compounds, R is selected from thegroup consisting of C₂-C₁₀ linear, branched, or cyclic, saturated orunsaturated alkyl groups with or without substituents, a C₅-C₁₀ aromaticgroup with or without substituents; an alkylamino group with or withoutsubstituents, and a C₃-C₁₀ heterocyclic group with or withoutsubstituents. Specific R groups include methyl, ethyl, propyl, allyl,butyl, dimethylamine group, and cyclic groups such as cyclopropyl,cyclobutyl, cyclopentyl, and cyclohexyl. Illustrative compounds arerepresented by the formulas:

In certain embodiments, R is an aromatic group such as, for example, aphenyl or a benzyl group.

The third class of organoaminosilane compound is represented by formulaC.

In Formula C, R and R1 are each independently R is selected from aC₁-C₁₀ linear, branched, cyclic, saturated, or unsaturated alkyl groupwith or without substituents; a C₅-C₁₀ aromatic group with or withoutsubstituents; or a C₃-C₁₀ heterocyclic group with or withoutsubstituents; R¹ is selected from a C₃-C₁₀ linear, branched, cyclic,saturated, or unsaturated alkyl group with or without substituents; aC₅-C₁₀ aromatic group with or without substituents; a C₃₋₁₀ heterocyclicaromatic group with or without substituents; a C₃-C₁₀ heterocyclic groupwith or without substituents; a hydrogen atom; or a silyl group withsubstituents; or wherein R and R¹ are combined into a heterocyclic groupvia formation of single or double carbon-carbon bond or linkage throughoxygen or nitrogen atom. In certain embodiments, R and R¹ are the same.In alternative embodiments, R and R¹ are different. The R² group bridgesthe nitrogen atoms. In certain embodiments, the R² group is nothing morethan a single bond between the nitrogen atoms. In an alternativeembodiment, the R² group it may be a bridging group, such as SiR₂, SiH₂,a chain, a ring, or a C₃-C₁₀ linear or a C₃-C₁₀ branched alkyl. In afurther embodiment of Formula C, R and R¹ can be linked together. In thelater embodiment, R and R¹ in Formula C can be combined into aheterocyclic group via formation of a single or a double carbon-carbonbond or a linkage through oxygen or nitrogen atom.

Specific examples include those represented by the formula C includesbut is not limited to:

It has been found though that even though the above organoaminosilanesare suitable for producing silicon oxide films on a semiconductorsubstrate, organoaminosilanes of formula A may be preferred for certainapplications. The dialkylaminosilanes described herein may also meet thecriteria of some of the prior silanes as precursors in that they formfilms having similar dielectric constants. In one particular embodiment,the particular organoaminosilane having Formula A diisopropylaminosilaneoffers excellent low etch rates which offers unexpected properties inthe process in that it is stable and has a longer shelf life than manyof the other silane precursors.

In Formulas A through C and throughout the description, the term “alkyl”denotes a linear, branched, or cyclic functional group having from 1 to10, or from 3 to 10, or from 1 to 6 carbon atoms. Exemplary alkyl groupsinclude but are not limited to methyl, ethyl, propyl, isopropyl, butyl,isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl,tetradecyl, octadecyl, isopentyl, and tert-pentyl.

In Formulas A through C and throughout the description, the term “aryl”denotes a cyclic functional group having from 6 to 12 carbon atoms.Exemplary aryl groups include but are not limited to phenyl, benzyl,tolyl, and o-xylyl.

In Formulas A through C and throughout the description, the term“aromatic” group denotes a functional group having from 3 to 10, from 5to 10, or 6 to 10 carbon atoms. The term “aromatic group” includeshomocyclic or heterocyclic rings which can be substituted with aheteroatom (e.g., O, N, S, halogen atom, etc.), an alkyl group, analkoxy, and/or an alkyl-amino group. In other embodiments, the aromaticgroup is not substituted or is unsubstituted. Exemplary aromatic groupsinclude, but are not limited to, pyrrole, alkyl substituted pyrrole,imidozale, alkyl substituted imidozale, pyrozale, or analkyl-substituted pyrozale. Further exemplary aromatic groups include,but are not limited to, pyrrolidine, alkyl-substituted pyrrolidine,imidazolidine, alkyl substituted imidazolidine, oxazolidine, alkylsubstituted oxazolidine, piperidine, alkyl substituted piperidine,morpholine, alkyl substituted morpholine, piperazine, or alkylsubstituted piperazine.

In certain embodiments, one or more of the alkyl group, aryl group,and/or alkoxy group may be substituted or with substituents or have oneor more atoms or group of atoms substituted in place of a hydrogen atom.Exemplary substituents include, but are not limited to, oxygen, sulfur,phosphorus, halogen atoms (e.g., F, Cl, I, or Br), nitrogen, a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, and a C₁-C₁₀ alkyl-amino group. Inother embodiments, one or more of the alkyl group, aryl group,alkyl-amino group and/or alkyoxy group is unsubstituted.

In certain embodiments, one or more of the alkyl group and/or arylgroup, and/or alkoxy group may be saturated or unsaturated in Formulas Athrough C. With regard to the term “unsaturated”, one or more of thecarbon atoms within group can be unsaturated with one or morecarbon-carbon double bonds (alkenes) or one or more carbon-carbon triplebonds (alkynes).

The Formula A through Formula C organoaminosilane precursors may be madein a manner described in Applicants' application U.S. Publ. No.2006/0258173 which is incorporated herein by reference in its entirety.

In certain embodiments, the method described herein further comprisesone or more additional silicon-containing precursors other than theorganoaminosilane precursor having the above Formulas A through C.Examples of additional silicon-containing precursors include, but arenot limited to, organo-silicon compounds such as siloxanes (e.g.,hexamethyl disiloxane (HMDSO) and dimethyl siloxane (DMSO));organosilanes (e.g., methylsilane; dimethylsilane; vinyltrimethylsilane; trimethylsilane; tetramethylsilane; ethylsilane;disilylmethane; 2,4-disilapentane; 1,4-disilabutane; 2,5-disilahexane;2,2-disilylpropane; 1,3,5-trisilacyclohexane, and fluorinatedderivatives of these compounds; phenyl-containing organo-siliconcompounds (e.g., dimethylphenylsilane and diphenylmethylsilane);oxygen-containing organo-silicon compounds, e.g.,dimethyldimethoxysilane; 1,3,5,7-tetramethylcyclotetrasiloxane;1,1,3,3-tetramethyldisiloxane; 1,3,5,7-tetrasila-4-oxo-heptane;2,4,6,8-tetrasila-3,7-dioxo-nonane;2,2-dimethyl-2,4,6,8-tetrasila-3,7-dioxo-nonane;octamethylcyclotetrasiloxane; [1,3,5,7,9]-pentamethylcyclopentasiloxane;1,3,5,7-tetrasila-2,6-dioxo-cyclooctane; hexamethylcyclotrisiloxane;1,3-dimethyldisiloxane; 1,3,5,7,9-pentamethylcyclopentasiloxane;hexamethoxydisiloxane, and fluorinated derivatives of these compounds.

Depending upon the deposition method, in certain embodiments, the one ormore silicon-containing precursors may be introduced into the reactor ata predetermined molar volume, or from about 0.1 to about 1000micromoles. In this or other embodiments, the silicon-containingprecursor may be introduced into the reactor for a predetermined timeperiod, or from about 0.001 to about 500 seconds.

As previously mentioned, the dielectric films deposited using themethods described herein are formed in the presence of oxygen using anoxygen source, oxidizing agent or precursor comprising oxygen. An oxygensource may be introduced into the reactor in the form of at least oneoxygen source and/or may be present incidentally in the other precursorsused in the deposition process. Suitable oxygen source gases mayinclude, for example, water (H₂O) (e.g., deionized water, purifierwater, and/or distilled water), oxygen (O₂), oxygen plasma, ozone (O₃),NO, NO₂, hydrogen peroxide, carbon monoxide (CO), carbon dioxide (CO₂)and combinations thereof. In certain embodiments, the oxygen sourcecomprises an oxygen source gas that is introduced into the reactor at aflow rate ranging from about 1 to about 2000 square cubic centimeters(sccm) or from about 1 to about 1000 sccm. The oxygen source can beintroduced for a time that ranges from about 0.1 to about 100 seconds.In one particular embodiment, the oxygen source comprises water having atemperature of 10° C. or greater. In embodiments wherein the film isdeposited by an ALD or a cyclic CVD process, the precursor pulse canhave a pulse duration that is greater than 0.01 seconds, and the oxygensource can have a pulse duration that is less than 0.01 seconds, whilethe water pulse duration can have a pulse duration that is less than0.01 seconds. In yet another embodiment, the purge duration between thepulses that can be as low as 0 seconds or is continuously pulsed withouta purge in-between. The oxygen source or reagent is provided in amolecular amount less than a 1:1 ratio to the silicon precursor, so thatat least some carbon is retained in the as deposited dielectric film. Ina further embodiment, the oxidizing agent to silane precursor ratio isgreater than 0.1, preferably from 0.1 to 6 moles oxidizing agent permole of organoaminosilane precursor.

In certain embodiments, the silicon and oxide film further comprisesnitrogen. In this embodiments, an additional gas such as a nitrogensource gas may be introduced into the reactor. Examples of nitrogensource gases may include, for example, NO, NO₂, ammonia, ammonia plasma,hydrazine, monoalkylhydrazine, dialkylhydrazine, and combinationsthereof.

The deposition methods disclosed herein may involve one or more purgegases. The purge gas, which is used to purge away unconsumed reactantsand/or reaction byproducts, is an inert gas that does not react with theprecursors. Exemplary inert gases include, but are not limited to, Ar,N₂, He, neon, H₂ and mixtures thereof. In certain embodiments, a purgegas such as Ar is supplied into the reactor at a flow rate ranging fromabout 10 to about 2000 sccm for about 0.1 to 1000 seconds, therebypurging the unreacted material such as, but not limited to, one or moreprecursors, oxygen source, etc. and any byproduct that may remain in thereactor.

In certain embodiments of the method described herein, the temperatureof the reactor or a deposition chamber may range from ambienttemperature (e.g., 25° C.) to about 700° C. Exemplary reactortemperatures for the ALD or CVD deposition include ranges having any oneor more of the following endpoints: 25, 50, 75, 100, 125, 150, 175, 200,225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550,575, 600, 625, 650, 675, or 700° C. Examples of particular reactortemperature ranges include but are not limited to, 25° C. to 375° C., orfrom 75° C. to 700° C., or from 325° C. to 675° C. In this or otherembodiments, the pressure may range from about 0.1 Torr to about 100Torr or from about 0.1 Torr to about 5 Torr. In one particularembodiment, the dielectric film is deposited using a thermal CVD processat a pressure ranging from 100 mTorr to 600 mTorr. In another particularembodiment, the dielectric film is deposited using an ALD process at atemperature range of 1 Torr or less.

In certain embodiments of the method described herein, the temperatureof the substrate in the reactor or a deposition chamber, may range fromambient temperature (e.g., 25° C.) to about 700° C. Exemplary substratetemperatures for the ALD or CVD deposition include ranges having any oneor more of the following endpoints: 25, 50, 75, 100, 125, 150, 175, 200,225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550,575, 600, 625, 650, 675, or 700° C. Examples of particular substratetemperature ranges include but are not limited to, 25° C. to 375° C., orfrom 75° C. to 700° C., or from 325° C. to 675° C. In certainembodiments, the substrate temperature may be the same as or in the sametemperature range as the reactor temperature during the deposition. Inother embodiments, the substrate temperature differs from the reactortemperature during the deposition.

The respective step of supplying the precursors, the oxygen source,and/or other precursors, source gases, and/or reagents may be performedby changing the time for supplying them to change the stoichiometriccomposition of the resulting dielectric film.

Energy is applied to the at least one of the precursor, oxygen source,reducing agent, other precursors or combination thereof to inducereaction and to form the dielectric film or coating on the substrate.Such energy can be provided by, but not limited to, thermal, plasma,pulsed plasma, helicon plasma, high density plasma, inductively coupledplasma, X-ray, e-beam, photon, and remote plasma methods. In certainembodiments, a secondary RF frequency source can be used to modify theplasma characteristics at the substrate surface. In embodiments whereinthe deposition involves plasma, the plasma-generated process maycomprise a direct plasma-generated process in which plasma is directlygenerated in the reactor, or alternatively a remote plasma-generatedprocess in which plasma is generated outside of the reactor and suppliedinto the reactor. In certain embodiments wherein a plasma is used, theRF power in the plasma chamber may range between 100 W and 1500 W.

The organoaminosilane precursors and/or other precursors may bedelivered to the reaction chamber such as a CVD or ALD reactor in avariety of ways. In one embodiment, a liquid delivery system may beutilized. In an alternative embodiment, a combined liquid delivery andflash vaporization process unit may be employed, such as, for example,the turbo vaporizer manufactured by MSP Corporation of Shoreview, Minn.,to enable low volatility materials to be volumetrically delivered,leading to reproducible transport and deposition without thermaldecomposition of the precursor. In liquid delivery formulations, theprecursors described herein may be delivered in neat liquid form, oralternatively, may be employed in solvent formulations or compositionscomprising same. Thus, in certain embodiments the precursor formulationsmay include solvent component(s) of suitable character as may bedesirable and advantageous in a given end use application to form a filmon a substrate.

The Formula A through C aminosilane precursors described herein canfurther comprise at least one pressurizable vessel fitted with theproper valves and fittings to allow the delivery of one or moreprecursors or chemical reagents to the process reactor. In certainembodiments, the contents of the vessel(s) can be premixed.Alternatively, the precursors can be maintained in separate vessels orin a single vessel having separation means for maintaining theprecursors separate during storage. Such vessels can also have means formixing the precursors when desired. The precursors can be pre-mixed andthen delivered to the reaction chamber, or alternatively, deliveredseparately wherein the mixture is formed in-situ within the reactionchamber and/or on the deposited film itself.

In one particular embodiment, the silicon-containing film is depositedusing a low pressure chemical vapor deposition process. Low pressurechemical vapor deposition processes (LPCVD) involve chemical reactionsthat are allowed to take place on a variety of substrates, e.g., siliconand aluminum, within a pressure range generally of from 0.1 to 500 torr,preferably from 0.5 to 20 Torr. High pressure CVD may result in gasphase nucleation or predeposition before the desired substrate isreached. Dilution of the silane precursor with inert gases, such asnitrogen and helium, may be required for such high pressure reactions.The use of inert gases by the fabricator to achieve correspondingdilution of the precursor may improve the conformality of the depositionor improve the penetration for chemical vapor infiltration. By using anisopropylaminosilane, and preferably diisopropylaminosilane as aparticular silane precursor, one can form an oxide film which depositsat a rate of 5 Å/min to 60 Å/min with refractive index in the range 1.45to 1.70, and wet etch rate (in 1% HF solution) in the range 0.01Å/second to 1.5 Å/second.

In a typical ALD or CCVD process, the substrate such as a silicon oxidesubstrate is heated on a heater stage in a reaction chamber that isexposed to the silicon-containing precursor initially to allow thecomplex to chemically adsorb onto the surface of the substrate.

A purge gas such as argon purges away unabsorbed excess complex from theprocess chamber. After sufficient purging, an oxygen source may beintroduced into reaction chamber to react with the absorbed surfacefollowed by another gas purge to remove reaction by-products from thechamber. The process cycle can be repeated to achieve the desired filmthickness.

In this or other embodiments, it is understood that the steps of themethods described herein may be performed in a variety of orders, may beperformed sequentially or concurrently (e.g., during at least a portionof another step), and any combination thereof. The respective step ofsupplying the precursors and the oxygen source gases may be performed byvarying the duration of the time for supplying them to change thestoichiometric composition of the resulting dielectric film.

In another embodiment of the method disclosed herein, the dielectricfilms is formed using a ALD deposition method that comprises the stepsof:

introducing an at least one organoaminosilane precursor represented bythe formulas:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic,saturated or unsaturated alkyl group with or without substituents; aC₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀heterocyclic group with or without substituents, or a silyl group informula C with or without substituents, R¹ is selected from a C₃-C₁₀linear, branched, cyclic, saturated or unsaturated alkyl group with orwithout substituents; a C₅-C₁₀ aromatic group with or withoutsubstituents, a C₃-C₁₀ heterocyclic group with or without substituents,a hydrogen atom, a silyl group with substituents and wherein R and R¹ informula A also being combinable into a cyclic group comprising from 2 to6 carbon atoms and R² representing a single bond, (CH₂), chain, a ring,SiR₂, or SiH₂; and

chemisorbing the at least one organoaminosilane precursor onto asubstrate;

purging away the unreacted at least one organoaminosilane precursorusing a purge gas;

providing an oxygen source to the organoaminosilane precursor onto theheated substrate to react with the sorbed at least oneorganoaminosilaneprecursor; and

optionally purging away any unreacted oxygen source.

The above steps define one cycle for the method described herein; andthe cycle can be repeated until the desired thickness of a dielectricfilm is obtained. In this or other embodiments, it is understood thatthe steps of the methods described herein may be performed in a varietyof orders, may be performed sequentially or concurrently (e.g., duringat least a portion of another step), and any combination thereof. Therespective step of supplying the precursors and oxygen source may beperformed by varying the duration of the time for supplying them tochange the stoichiometric composition of the resulting dielectric film,although always using oxygen in less than a stoichiometric amountrelative to the available silicon.

For multi-component dielectric films, other precursors such assilicon-containing precursors, nitrogen-containing precursors, reducingagents, or other reagents can be alternately introduced into the reactorchamber. In a further embodiment of the method described herein, thedielectric film is deposited using a thermal CVD process. In thisembodiment, the method comprises: placing one or more substrates into areactor which is heated to a temperature ranging from ambienttemperature to about 700° C. and maintained at a pressure of 1 Torr orless; introducing at least one silicon precursor selected from asilicon-containing precursor having the following formula represented bythe formulas:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic,saturated or unsaturated alkyl group with or without substituents; aC₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀heterocyclic group with or without substituents, or a silyl group informula C with or without substituents, R¹ is selected from a C₃-C₁₀linear, branched, cyclic, saturated or unsaturated alkyl group with orwithout substituents; a C₅-C₁₀ aromatic group with or withoutsubstituents, a C₃-C₁₀ heterocyclic group with or without substituents,a hydrogen atom, a silyl group with substituents and wherein R and R¹ informula A also being combinable into a cyclic group comprising from 3 to10 carbon atoms and R² representing a single bond, (CH₂), chain, a ring,C₃-C₁₀ branched alkyl, SiR₂, or SiH₂, to deposit a dielectric film ontothe one or more substrates wherein the reactor is maintained at apressure ranging from 100 mTorr to 600 mTorr during the introducingstep.

In certain embodiments, the resultant dielectric films or coatings canbe exposed to a post-deposition treatment such as, but not limited to, aplasma treatment, chemical treatment, ultraviolet light exposure,electron beam exposure, and/or other treatments to affect one or moreproperties of the film.

The dielectric films described herein have a dielectric constant of 6 orless. Preferably, the films have a dielectric constant of about 5 orbelow, or about 4 or below, or about 3.5 or below.

As mentioned previously, the method described herein may be used todeposit a dielectric film on at least a portion of a substrate. Examplesof suitable substrates include but are not limited to, silicon, SiO₂,Si₃N₄, OSG, FSG, silicon carbide, hydrogenated silicon carbide, siliconnitride, hydrogenated silicon nitride, silicon carbonitride,hydrogenated silicon carbonitride, boronitride, antireflective coatings,photoresists, organic polymers, porous organic and inorganic materials,metals such as copper and aluminum, and diffusion barrier layers such asbut not limited to TiN, Ti(C)N, TaN, Ta(C)N, Ta, W, or WN. The films arecompatible with a variety of subsequent processing steps such as, forexample, chemical mechanical planarization (CMP) and anisotropic etchingprocesses.

The deposited dielectric films have applications, which include, but arenot limited to, computer chips, optical devices, magnetic informationstorages, coatings on a supporting material or substrate,microelectromechanical systems (MEMS), nanoelectromechanical systems,thin film transistor (TFT), and liquid crystal displays (LCD).

The following examples are provided to illustrate various embodiments ofthe invention and are not intended to restrict the scope thereof.

EXAMPLES General Procedure

The precursors were tested in an LPCVD reactor used to qualifyexperimental precursors for silicon oxide depositions. The precursorswere degassed and metered into the reactor through a low-pressure massflow controller (MFC). The MFC flows were calibrated against weightlosses of the chemicals vs. time of flow. Additional reactants, such asoxygen, and diluents, such as nitrogen and helium, were also meteredinto the reactor through calibrated MFCs. The reactor was connected to aroots blower/dry pump combination capable of evacuating the reactor tobelow 1E-4 Torr (0.013 Pa). The temperature across a load of siliconwafers, during deposition, was within 1° C. of the set point.

The wafers were loaded onto a quartz boat and inserted in the reactor.The reactor is pumped to base pressure and checked for leaks. The systemwas ramped to the process temperature with gas flows that would diluteany residual oxygen or moisture to prevent any oxidation of the siliconwafers as the reactor heats up. The reactor was then stabilized for apredetermined time to bring all wafer surfaces to an equal temperatureas had been determined by previous measurements on wafers with attachedthermocouples.

The gases and vapors were injected into the reactor for a predetermineddeposition time at a controlled pressure. Next, the gases were shut off,and the reactor pumped to a base pressure. The reactor then waspump-purged, pumped down, and pump-purged to clear any reactive gasesand vapors as the reactor was cooled down. The reactor was backfilled toatmospheric pressure; the wafers were removed and allowed to cool toroom temperature. The deposited films were then measured for filmthickness, film refractive index, film stress, infrared absorbances,dielectric constant, and acid etch rate.

Example 1 Formation of Silicon Oxide Film Using DiethylaminosilanePrecursor

The general procedure outlined above was followed using the followingreactants and flow conditions. 11.7 sccm of diethylaminosilane (DEAS)was flowed into the LPCVD reactor at 500° C. with 5.9 sccm O₂ at 0.6Torr for a deposition time of 74 minutes.

The average film thickness of the silicon oxide film was 123 nm andrefractive index was 1.459. The wet etch rate of this film in 1% HFsolution was 1.38 Å/second. The infrared spectra were dominated bySi—O—Si absorptions. C—H absorptions were in the noise, indicating thefilm was silicon dioxide. Film composition analysis by Rutherfordbackscattering spectroscopy (hydrogen by forward scattering) indicatedthat this film was 28 atom percent silicon, 57 atom percent oxygen, 11atom percent hydrogen, 3 atom percent carbon, and 1 atom percentnitrogen, indicating that the film was silicon dioxide with hydrogen,carbon, and nitrogen impurities.

Example 2 Formation of Silicon Oxide Film Using DiethylaminosilanePrecursor

The procedure of Example 1 was followed with the exception of processconditions. The purpose was to determine the effect of a highertemperature and reduced reaction time. In this example, 11.7 sccm ofdiethylaminosilane (DEAS) was flowed into a reactor at 600° C. with 5.9sccm O₂ at 0.6 Torr for a deposition time of 33 minutes.

The average film thickness of the silicon oxide film was 157 nm and therefractive index was 1.501. The wet etch rate of this film in 1% HFsolution was 0.41 Å/second. The infrared spectra were dominated bySi—O—Si absorptions. C—H absorptions were in the noise, indicating thefilm was silicon oxide. Film composition analysis by Rutherfordbackscattering spectroscopy (hydrogen by forward scattering) indicatedthat this film was 27 atom percent silicon, 47 atom percent oxygen, 15atom percent hydrogen, 7 atom percent carbon, and 4 atom percentnitrogen, indicating that the film was silicon dioxide with hydrogen,carbon, and nitrogen impurities.

Example 3 Formation of Silicon Oxide Film Using DiisopropylaminosilanePrecursor

The procedure of Example 1 was followed essentially with the exceptionof process conditions and the precursor. In this example, 10.5 sccm ofdiisopropylaminosilane (DIPAS) was flowed into a reactor at 500° C. with5.0 sccm O₂ at 0.6 Torr for a deposition time of 74 minutes.

The average film thickness of the silicon oxide film was 112 nm andrefractive index was 1.458. The wet etch rate of this film in 1% HFsolution was 1.39 Å/second. The infrared spectra were dominated bySi—O—Si absorptions. C—H absorptions were in the noise, indicating thefilm was silicon oxide. Film composition analysis by Rutherfordbackscattering spectroscopy (hydrogen by forward scattering) indicatedthat this film was 28 atom percent silicon, 55 atom percent oxygen, 12atom percent hydrogen, 3 atom percent carbon, and 2 atom percentnitrogen, indicating that the film was silicon dioxide with hydrogen,carbon, and nitrogen impurities.

Example 4 Formation of Silicon Oxide Film Using DiisopropylaminosilanePrecursor

The procedure of Example 2 was followed with the exception of processconditions and the precursor. In this example, 10.5 sccm ofdiisopropylaminosilane (DIPAS) was flowed into a reactor at 600° C. with5.0 sccm O₂ at 0.6 Torr for a deposition time of 33 minutes.

The average film thickness of the silicon oxide film was 124 nm andrefractive index was 1.495. The wet etch rate of this film in 1% HFsolution was 0.42 Å/second. The infrared spectra were dominated bySi—O—Si absorptions. C—H absorptions were in the noise, indicating thefilm was silicon oxide. Film composition analysis by Rutherfordbackscattering spectroscopy (hydrogen by forward scattering) indicatedthat this film was 28 atom percent silicon, 51 atom percent oxygen, 11atom percent hydrogen, 6 atom percent carbon, and 4 atom percentnitrogen, indicating that the film was silicon dioxide with hydrogen,carbon, and nitrogen impurities.

In summary, Examples 1 through 4 show that an organoaminosilane of thetype set forth in formula A may be used as a precursor for producingsilicon oxide films on a semiconductor substrate. Thediisopropylaminosilane, DIPAS, offers advantages to the use ofdiethylaminosilane (DEAS) as a precursor in a low etch rate oxideprocess. DEAS is less stable than DIPAS at room temperature. Theinstability of DEAS can result in many EH&S management, production,supply line (including warehousing and shipping), and end user processchallenges. Examples 3 and 4 show the oxide films formed from DIPASgenerally have the same etch rates, dielectric constants, refractiveindex, and qualitative composition (via FTIR) as the oxide films formedfrom DEAS in Examples 1 and 2 under similar process conditions. Thus,from both chemical and process viewpoints, DIPAS is a preferredprecursor for producing low etch rate silicon oxide films.

Example 5 Atomic Layer Deposition of Silicon Oxide Films

ALD depositions using various organoaminosilane precursors in themonoaminosilane and bisaminosilane classifications as comparatives andthe results of the depositions are provided in Table II. Attempts todeposit the bisaminosilanes bis(di-sec-butylamino)silane andbis(di-n-butylamino)silane and the trisaminosilanetris-(di-n-butylamino)silane were unsuccessful because the vaporpressure of these precursors was too low for precursor delivery. Thedepositions were performed on a laboratory scale ALD processing tool ateither 150° C. or 300° C. for either 500 or 1,000 process cycles withozone as the oxygen source gas (see Table II for temperature and numberof process cycles). The resultant SiO₂ films were characterized fordeposition rate, wet etch rate, refractive index, and % non-uniformityand the results are also provided in Table II. The process steps thatwere used to deposit the SiO₂ films are shown in the following Table I.

TABLE I Process for Generating Basic ALD Oxide Films with O₃ Step 6 secNitrogen Purge of Flow 1.5 Purges out unreacted 1 Reactor slpm N2chemical from reactor Step 6 sec Chamber evacuation <100 mT Preps thereactor for the 2 precursor dose Step 2 sec Close throttle valveIncreases precursor 3 resonance time Step vari- Dose Reactor pressuretypically 4 able Organoaminosilane <1 T during dose Precursor Step 6 secNitrogen Purge of Flow 1.5 Purges out unreacted 5 Reactor slpm N2chemical from reactor Step 6 sec Chamber evacuation <100 mT Preps thereactor for the 6 precursor dose Step 2 sec Close throttle valveIncreases precursor 7 resonance time Step 2 sec Dose Ozone O₃ at 15-17%post 8 generator, P =< 8 T

The resultant SiO₂ films were characterized for deposition rate, wetetch rate, refractive index, and % non-uniformity and the results arealso provided in Table II. In Table II, the refractive index of thefilms was measured using a FilmTek 2000SE ellipsometer by fitting thereflection data from the film to a pre-set physical model (e.g., theLorentz Oscillator model). For refractive index, a value of around 1.44to 1.47 would reflect a typical CVD silicon oxide film. All of theprecursors tested deposited films having a refractive index of rangingfrom about 1.4 to about 1.5. The % non-uniformity quoted was obtainedfrom a 9-point map using the standard equation: %non-uniformity=((max−min)/(2*mean)).

In Table II, the wet etch test of silicon oxide films or WER wasperformed using a 1% HF solution. Thermal oxide wafers were used asreference for the etch test. The films, along with the comparativesilicon oxide films, are measured for their thickness at 9 differentpoints across the film surface before and after etch using anellipsometer. The etch rate is then calculated as the thicknessreduction divided by the time that the films are immersed into the HFsolution.

For the precursors containing the substituent diispropyl, the results inTable II show that the monoaminosilane precursor or DIPAS had asignificantly greater deposition rate compared to the bisaminosilaneprecursor or BisDIPAS. A higher deposition rate is a desired propertyfor the semiconductor industry. Thus, for precursors having the samesubstituent diisopropyl, the higher deposition rate indicates thatprecursors having the SiH₃ group are more reactive than the precursorshaving the SiH₂ group.

For the precursors containing the substituent diispropyl, the results inTable II also show that the monoaminosilane precursor or DIPAS had alower % non-uniformity compared to the bisaminosilane precursor orBisDIPAS. Lower % non-uniformity is a desired property for thesemiconductor industry.

The characterization of the chemical composition of the films depositedusing various precursors or film nos. 2 and 4 deposited from DIPAS, filmnos. 9 and 10 deposited from BisDIPAS, film no. 12 deposited from DSBAS,and film no. 17 deposited from DNBAS was performed using a PhysicalElectronics 5000VersaProbe XPS Spectrometer, which is equipped withmulti-channel plate detectors (MCD) and an Al monochromatic X-ray sourceand the results are presented in Table III. The XPS data shows that thefilms deposited from the various aminosilane precursors had comparablefilm composition, with no gross C or N contamination.

FTIR data was obtained for silicon dioxide films deposited from theprecursors DIPAS (film Nos. 5 and 6), BisDIPAS (film Nos. 7 and 8) andDNBAS (film Nos. 16 and 18) and the results of this data are provided inFIGS. 1 a (150° C. depositions) and 1 b (300° C. depositions). FTIR datawas collected on the films using a Thermo Nicolet Nexus 470 systemequipped with a DTGS KBR detector and KBr beam splitter. The FTIRspectra in FIGS. 1A and 1B support the XPS data, indicating that allfilms produced are of similar silicon oxide structure.

Additional film characterization was conducted on DIPAS film no. 2, 98(BisDIPAS film no. 12), DSBAS film no. 12, and DNBAS film no. 17 viasecondary ion mass spectrometry (SIMS). The SIMS data established thatthe films deposited from the various aminosilane precursors hadcomparable film composition, with no gross C or N contamination whichconfirms the XPS shown in Table III and FTIR data shown in FIGS. 1A and1B.

TABLE II ALD Deposition Results Deposition Wet Etch Refrac- Film RateRate tive % Non- No. Precursor (Å/cycle) (Å/min.) Index Uniformity 1DIPAS 1.576 306.00 1.4503 1.33 150° C./500 cycles 2 DIPAS 1.825 294.001.4587 0.82 150° C./1000 cycles 3 DIPAS 1.582 372.00 1.4355 1.07 300°C./500 cycles 4 DIPAS 1.881 322.20 1.4480 0.64 300° C./1000 cycles 5DIPAS 1.508 330.00 1.4663 0.93 150° C./500 cycles 6 DIPAS 1.605 434.001.4411 0.62 300° C./500 cycles 7 BisDIPAS 0.469 364.20 1.4985 2.56 300°C./500 cycles 8 BisDIPAS 0.181 312.00 1.5161 11.60 150° C./500 cycles 9BisDIPAS 0.827 352.20 1.4490 1.93 300° C./1000 cycles 10 BisDIPAS 0.243316.20 1.5178 10.27 150° C./1000 cycles 11 DSBAS 1.206 306.00 1.43492.40 150° C./500 cycles 12 DSBAS 1.619 286.20 1.4332 1.36 150° C./1000cycles 13 DSBAS 1.142 328.20 1.4353 3.15 300° C./500 cycles 14 DSBAS1.585 318.00 1.4513 1.04 300° C./1000 cycles 16 DNBAS 1.681 265.801.4524 1.07 150° C./500 cycles 17 DNBAS 1.848 271.80 1.4576 0.87 150°C./1000 cycles 18 DNBAS 1.374 355.80 1.4580 1.24 300° C./500 cycles 19DNBAS 1.860 322.20 1.4580 0.73 300° C./1000 cycles

TABLE III Atomic composition for silicon oxide films deposited by ALDfrom various aminosilane precursors. C O Si N Film No. Precursor 1s 1s2p 1s 12 (Di-secbutylamino)silane — 67.6 32.4 — 150° C./1000 cycles 2(Di-isopropylamino)silane — 68.1 31.9 — 150° C./1000 cycles 4(Di-isopropylamino)silane — 67.5 32.5 — 300° C./1000 cycles 17(Di-n-butylamino)silane — 68.0 32.0 — 150° C./1000 cycles 10 Bis(Di- —68.0 32.0 — isopropylamino)silane 150° C./1000 cycles 9 Bis(Di- — 68.032.0 — isopropylamino)silane 300° C./1000 cycles

Example 6 Comparison of Deposition and Resultant Silicon Oxide Films forFormula A (DIPAS), Formula B (N-(2-Pyridino)disilazane), and Formula C(7,9-disilyl-7,9-diaza-8-sila-bicyclo[4,3,0]nonane) Precursors

The general procedure outlined above for LPCVD of silicon oxide films inExample 1 was followed using the reactants and flow conditions providedin Table IV. The deposited silicon oxide films were then evaluated andthe results of the evaluations are also provided in Table IV. For eachof the films, the wet etch rate was determined using a 1:99 HF/H20solution, or 1 part 49% HF to 99 parts water and was compared to athermal oxide WER of 0.5 Å/second. The wet etch rate was compared to athermal baseline film to verify the acid concentration and an equivalentWER for each test.

For the Formula B precursor or N-(2-Pyridino)disilazane, the averagefilm thickness of the silicon oxide film was 4586 Å and refractive indexwas 1.5696. The deposition rate was approximately 51 Å per minute. Thewet etch rate of this film in a 1:99 HF/H20 solution, or 1 part 49% HFto 99 parts water, was 24 Å/second compared to a thermal oxide WER of0.5 Å/second. By comparison, the Formula A precursor ordiisopropylaminosilane (DIPAS) had a WER of approximately 3 Å/min andthe formula C precursor having the chemical name7,9-disilyl-7,9-diaza-8-sila-bicyclo[4,3,0]nonane, had a WER of 0.8Å/min.

For the Formula B and Formula C precursors, the infrared spectra weredominated by Si—O—Si absorptions. C—H absorptions were in the noise,indicating the film was silicon oxide. Film composition analysis byX-ray Photospectroscopy (XPS) indicated that this film was 30.6 atompercent silicon, 51.3 atom percent oxygen, 12.5 atom percent carbon, and5.6 atom percent nitrogen, indicating that the film was silicon dioxidewith carbon and nitrogen impurities.

TABLE IV Precursor Formula A Precursor Precursor C (DIPAS) Formula BFormula C Precursor Flow 11.2 13.7 15 (sccms) Oxygen flow 20 20 20(sccms) Reactor 475 475 550 Temperature (° C.) Reactor Pressure 250 250250 (mTorr) Deposition time 180 90 60 (minutes) Deposition rate 12 51 25(Å/min) Refractive Index 1.4589 1.5696 1.5687 WER in 1:99 2.3 25 0.9HF:H₂O (Å/sec) XPS O 1s 67.5 51.3 51.5 XPS Si 2p 32.5 30.6 32.1 XPS C 1sND 12.5 9.6 XPS N 1s ND 5.6 6.9

Example 7 Atomic Layer Deposition of Silicon Oxide Films Using Formula Bprecursors Diphenyldisilazane and N-(2-Pyridino)disilazane)

ALD depositions of silicon oxide films using two Formula Borganoaminosilanes or diphenyldisilazane and N-(2-Pyridino)disilazane)and ozone were conducted and the results of these depositions areprovided in Table V. The process steps that were used to deposit theSiO₂ films were similar to that in Table I of Example 5. The depositionswere performed on a laboratory scale ALD processing tool at either 150°C. or 300° C. for either 500 or 1,000 process cycles with ozone as theoxygen source gas (see Table V for deposition temperature and number ofprocess cycles). The resultant SiO₂ films were characterized fordeposition rate, refractive index, and % non-uniformity in the mannerdescribed in Example 5 and the results of the characterizations are alsoprovided in Table V.

TABLE V ALD Deposition Results Deposition Refractive % Non-Organoaminosilane Precursor Rate (Å/cycle) Index UniformityN-Phenyldisilazane 150° C./500 0.132 1.7242 21.32 cyclesN-Phenyldisilazane 300° C./500 0.216 1.5293 12.98 cyclesN-(2-Pyridino)disilazane) 1.5 1.4562 1.13 (1 second Dose) 300° C./500cycles N-(2-Pyridino)disilazane) 1.656 1.4558 0.65 (2 seconds Dose) 300°C./500 cycles

The invention claimed is:
 1. A method for forming a silicon oxide film on a substrate via a vapor deposition process, the method comprising: introducing an organoaminosilane represented by the formulas:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic, saturated or unsaturated alkyl group with or without substituents; a C₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀ heterocyclic group with or without substituents, or a silyl group in formula C with or without substituents, R¹ is selected from a C₃-C₁₀ linear, branched, cyclic, saturated or unsaturated alkyl group with or without substituents; a C₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀ heterocyclic group with or without substituents, a hydrogen atom, a silyl group with substituents and wherein R and R¹ in formula A also being combinable into a cyclic group comprising from 2 to 6 carbon atoms and R² representing a single bond, (CH₂), chain, a ring, C₃-C₁₀ branched alkyl, SiR₂, or SiH₂ into a deposition chamber; introducing at least one oxidizing agent into the deposition chamber wherein the at least one oxidizing agent reacts with the organoaminosilane to provide the silicon oxide film on the substrate wherein the vapor deposition process is at least one selected from the group consisting of at least one selected from chemical vapor deposition, low pressure vapor deposition, plasma enhanced chemical vapor deposition, cyclic chemical vapor deposition, plasma enhanced cyclic chemical vapor deposition, atomic layer deposition, and plasma enhanced atomic layer deposition, and wherein the vapor deposition process is conducted at one or more temperatures ranging from 25° C. to 375° C.
 2. The method of claim 1 wherein the vapor deposition process comprises a plasma.
 3. The method of claim 2 wherein the plasma is directly generated in the deposition chamber.
 4. The method of claim 2 wherein the plasma is generated outside of the deposition chamber and supplied into the deposition chamber.
 5. A composition for depositing a silicon-containing film by a vapor deposition process, the composition comprising: an organoaminosilane precursor represented by the following formula A:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic, saturated or unsaturated alkyl group with or without substituents; a C₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀ heterocyclic group with or without substituents and R¹ is selected from a C₃-C₁₀ linear, branched, cyclic, saturated or unsaturated alkyl group with or without substituents; a C₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀ heterocyclic group with or without substituents, a hydrogen atom, a silyl group with substituents and wherein R and R¹ in formula A also being combinable into a cyclic group; a gas selected from the group consisting of an inert gas and nitrogen.
 6. The composition of claim 5 wherein R and R¹ in Formula A are each independently selected from the group consisting of isopropyl, t-butyl, sec-butyl, t-pentyl, and sec-pentyl groups.
 7. The composition of claim 6 wherein R and R¹ in Formula A are each isopropyl.
 8. The composition of claim 6 wherein R and R¹ in Formula A are each sec-butyl.
 9. The composition of claim 5 wherein R and R¹ in Formula A are combined into a cyclic group.
 10. A composition for depositing a silicon-containing film in a vapor deposition process, the composition comprising: an organoaminosilane precursor represented by the following formula; and

a gas selected from the group consisting of an inert gas and nitrogen.
 11. The composition of claim 10 wherein the gas comprises the inert gas.
 12. The composition of claim 11 wherein the inert gas comprises helium.
 13. The composition of claim 10 wherein the composition is contained in a pressurizable vessel fitted with the proper valves and fittings to allow delivery of to the process reactor.
 14. A precursor formulation comprising: an organoaminosilane represented by the formulae:

wherein R is selected from a C₁-C₁₀ linear, branched, or cyclic, saturated or unsaturated alkyl group with or without substituents; a C₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀ heterocyclic group with or without substituents, or a silyl group in formula C with or without substituents, R¹ is selected from a C₃-C₁₀ linear, branched, cyclic, saturated or unsaturated alkyl group with or without substituents; a C₅-C₁₀ aromatic group with or without substituents, a C₃-C₁₀ heterocyclic group with or without substituents, a hydrogen atom, a silyl group with substituents and wherein R and R¹ in formula A also being combinable into a cyclic group comprising from 2 to 6 carbon atoms and R² representing a single bond, (CH₂), chain, a ring, C₃-C₁₀ branched alkyl, SiR₂, or SiH₂ into a deposition chamber; and a solvent. 